Plan A was simple enough, a time-honored fight to the death between Kara and Rhea, to the victor goes the planet. But when Rhea proved — gasp! — less than trustworthy (“My gods only care about my victory,” she declared), Kara was forced to resort to the far-less-desirable Plan B, one which threatened her future with Mon-El.

By recalibrating a device her brother originally created to make the environment uninhabitable for Kryptonians, Lena was able to make the atmosphere toxic to Daxamites. And while this took care of the immediate problem — bye, Rhea! — it also meant that Mon-El would have to leave the planet.

“Wherever I go, I’m going to be better because of you,” he told Kara during a tear-filled goodbye. “You’ll be in my heart.”

“You’ve made me so happy,” she replied, then gave him her necklace and finally dropped the L-bomb, acknowledging, “I should have said it before.”

Unfortunately, as is Supergirl tradition, Mon-El’s pod was *ahem* knocked off course in the episode’s final moments — and fell right into a portal to another dimension. (I’ve heard of long-distance relationships, but this seems like a little much.)

And now, for a quick rundown of the finale’s other (equally) major developments:

* Following Mon-El’s departure to Zod-knows-where, we were taken back 35 years to the destruction of Krypton. It turns out that Superman and Supergirl weren’t the only children released into space that day; there’s also a nasty little baddie named Reign that was shipped off — and something tells us we’ll be seeing a whole lot of her in Season 3.

* Kara’s heroic actions inspired Alex to make a bold move of her own, proposing to Maggie. (Well, she didn’t so much pop the question as she ordered Maggie to marry her, but that’s beside the point.) And while we didn’t get an official answer from Maggie, the huge grin on her face seemed to imply that she doesn’t hate the idea. #SanversWedding, anyone?

* And one of the show’s biggest mysteries has at last been solved: Cat Grant does know that Kara is Supergirl, which we learned towards the end of the episode when Cat — under her breath, of course — referred to Kara by her crimefighting alter ego. (As for when Cat finally put two and two together, your guess is as good as mine. But for someone who considers herself to be an observant journalist, I’m going to settle on “way too late.”)

* Speaking of Cat, I loved all her meta references in the finale. First came “I’ve never seen Star Wars,” a nod to Calista Flockhart’s husband Harrison Ford, followed by the reveal that Cat turned down two proposals from Rob Lowe, who played Flockhart’s husband on the Greg Berlanti-produced Brothers & Sisters.

What were your favorite moments from Monday’s jam-packed finale? And what are your hopes for Season 3? Grade the episode below, then drop a comment with your full review.